SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6830f97156149567d522d37ca0c9eb7e4459393e739f972f1892df49f4b6e4ae' 
  AND token = 'iwlnFYYYYw6rlAFXt0gTF/leEBKZpPlhC/2vosCzkXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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