SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d93008b46fae67a04930a11f7d09461293eee95d22fd2f277288b2477a126e1' 
  AND token = 'pbbISBYc+7oV0ut/xO4lNpDz+gZa86sanLp7bEgkb9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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