SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f66ddc29608bf6a556bda3aad3da7a34123d8af377841124f55656c84287cd5c' 
  AND token = 'wWo1i/2+3sHmVuY/zcDtXRYMYNusfQZLgzVJhjriQSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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