SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1246231e301348400c59d0903b82fc994c3bad72665f818932a3f20d28497237' 
  AND token = '/hjBqfgKg+vALZMx7fLssvEpyD+n3DJ8tua+55l1VWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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