SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f4324ebde60c1026318f40aab7123e0ef2588ee01ad6609f3ba2d3038edaa60' 
  AND token = 'faWYxmIT4Ai63/o3z5F6/4lQt2uuBvaIkh6gOZmB8Aw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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