SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69b635fb8a17e605ef79700f621bdefa280889ca7c3c9a920b41dbafa12686f7' 
  AND token = 'w7UC3uq7cSa4cZCRPzPmqv2qaUO8ObFn4Y+Niis18n0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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