SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7236c978d1482c22921ef96ab907cbbe8f9b406120b12da73a6e5b0ae392b628' 
  AND token = '5cLoKMJs/mbFxI+YbdRO3OqNrfg4WFc9a3pzNV8LE/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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