SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e77ae9d3c2cfc7eda202167fcf1ba483afec424f4cf0768f2fdeda972dcb4ede' 
  AND token = 'bSGZmvZYRt09wYtxL2JCitphIFSoIFdLWth5YLPZ0ho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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