SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e50a7765d0b1c35cc84c050c32de3a85e1a514fdd73b91b9d2a8859d1d42456e' 
  AND token = 'BvqW10nGpXvr/DO+fjMg9WBDvh8ZXzE8SunAJS/A1XM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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