SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae19ef0efe2f739ffb97265392ba1d7556511da8433289b940924bce146e0aef' 
  AND token = 'wzIE+AEuPCjg9KeWzWWW+uoVY0l/i55IW/iLf6ENGpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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