SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fcf30aa72c0fc2a9ec8194e0dc1ac57f759e0d2e48cac24c91e7e3e1a98ee1d' 
  AND token = 'jnhxJo0sDL9Ox46Av/c9Lpuzs0xRLrUZSFmrm3SfGgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}