SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f992847aaf0beb31b7df438a8ca5f4fa3186e714a0c0e5a0f06678ffb56a13d' 
  AND token = 'b99eHau/V1RmRZ/0kHLoqgMW1e+r4SG03zOORj4Wyj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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