Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a0cdbc653859724340378b35741f5a1dca7925a6b118125625984bbd2f50519' 
  AND token = '9dLeDigsXyOH38k4rRGsjfYH8djXGOoSChIsulnP6zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}