SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3d0b3e82427cac5b0a004cf882edf2e32843c6b26770a67dc3f9f60398361fd6' 
  AND token = '57sgcPmy5VEYnrrJNppq/8zjFN8zB7mtvQrGDMSCvXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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