SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2767415155631509ed4a86f6a158c54a98d863d96bbc9d40bffa579c5d6b7980' 
  AND token = 'YTPtYtLJQKo2YmaUBMKa8Sj1IfOgrL+PIFT3CmzdGo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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