SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99b90e2a7e5451ef59eb1494c2f6ee9db689e7cc2375dc00d64d2f7868795791' 
  AND token = 'kgOmlyToDbDpuj7szKjF4W8RlMqw/wBLjufGqCjElH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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