SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b82d0fa923f2345ec72a46a34698dec5257d99c82b9ba7945fc2387433020850' 
  AND token = 'VpRNzwjkn4TREDVpXPajQ+vzIOQUDczcHaHExGhp+oY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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