SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '16b71e96c946601a0e9a19281485396bb7b5af47787b1f3f1846c6ae502496b0' 
  AND token = 'ku/GO63SzSyMKuT7ZXYQlhU3zpupBuk/qtsOdaFQ/FQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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