SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2d667b09a7b828b78eb41e68b0ed9b6fc915e1af406edd445ef76d1a8acda89' 
  AND token = 'sVbZMfxCtUdm3zKx5swj8EddYAz2ljd7VX3sqoZe5eQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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