SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfacf5cf148f8be68f28eb517d52b3a4a98e0c8767818741102e10b06c397650' 
  AND token = 'l24wjA/QvtRj0Nz9INMs+ckh3h3OHxnYYzvzs/NGRLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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