SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fd381fb5659ff27f7bc8974a984e437a6ee92026b13f4cc53019d78ca0aac69' 
  AND token = 'VD5/fJWjviuP/EZkTjg8UY/MLEjYjdFAGUt5bGfMpSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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