SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd59452ebfb8d397d23f7d1c997a412242036d93d2287f5a93cafb48b162051f' 
  AND token = 'CaxR3+UG/JjZVjxZnggMwC6o/T3l2UFNfSMq1SG5T1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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