SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be5d349b9b4f165a212f06bf6cf2f4be90e97b9182ff51e34d31058c2a9fdba0' 
  AND token = 'jOf2yeszXsqbPlSM0lUzLXHqNtU8EAyIoxZlFKm89x4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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