SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab560a88158de57d878084d16f7c24dc8c6b203c764df3313d2916623099abc0' 
  AND token = 'gq8Tc+w7yMYQ4h2R4q1fA90cGQhPfaJYHZJK/0wRnAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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