SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3dcb8581f7c70cb57f5828a03dfd5b9dc91fb2d6c550f8b93e52482eeb7e56a' 
  AND token = 'm0SQkNgMD6sIC3jAFEhKqQ6GV5Mi9gXlHbirJf3N5i0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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