SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3186fd06f535ff8f2b26135c628c3bc69aa78bef36534e49743b01b99097ca33' 
  AND token = '5PnyY3Mk0PzdZKAGV8nu1aZxzaBcygrHx6+ywTZY/HQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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