SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcd2b44406b3c9e385b2b586cee287e17f7c1085bda6aaaa4e80b4d533ab2ccc' 
  AND token = 'Ffxde7ooW4CaDUsDdVxyoKRoAsF3SgV6grcScVGmPJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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