SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f6287dc5932171aae2d16b832c49afa7f007a56a562c76881b3fb7b4895f5c4' 
  AND token = '+kDpsimKzKA1mzt0zst9yYsjtH2tXaLCuzENIF+UDf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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