SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80368ec34f171b890b5b82fd8ed7b693937c52810c185a53a7d954dd4bfd4984' 
  AND token = '7OqdnE7UNYYLk/jdhBZ7GkqWrna1gWzGBj/By8Ju4gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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