SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7f1144ffd73a2bff2774350913c823a8ec5f5e712cf345003d32cde42d8d1412' 
  AND token = '9sQjbKc8uraj6smFg5QeYoSPI7hbQte28BTnre4sEOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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