SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a717602e86fbb4c1d50eb63adf49dd32d710b6d33eaf570281c09c48c54b925' 
  AND token = '5/PnWOCePM6nXMcnBfReNUoMuIj12w/YTBUO3NRfj0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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