SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2343438ac2c05da079bf4fae8562965753217e013e3cbe6a88418b94bdf80b8' 
  AND token = 'NmqqaHZkNf1We7NjnNMrj6n/418kmgHPcCmZ6hq4vfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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