SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '56ccdd506c1c2eac3e49987b4903366eee0cda0f045c02a3090a20d20dbf89aa' 
  AND token = 'NgTjreYN+Dej5rH0ZsDAJNKd4Ymr8vKdLAJfbLteJUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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