SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42f6e82b7f98f965ad661b9228dbb2935751f63b8b0ac0fd7b57cd6165bdc91f' 
  AND token = 'bsM4ZNnSkz7WyOZyLzv1L3M84kQbK1mmKPlSPp3C2XQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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