SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af67b08cb61e758ccb444b87458e2c03696abfea1678aa2a9ea5ddfa0790f36d' 
  AND token = 'hZWqv+peCjyVOw1VyOEZv0PGbsjNcqYDKBUPhWgK8ek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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