SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '58e96a23e64824eba87a24837735ddebd36b4326c2d01acca891bc61c94119a7' 
  AND token = 'RrSjuZlD/ePMehGBMlplb7zzWje3nNXelfydmB7UlfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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