SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '740e5edf0c2e6e5a0c46e6e275a4b79410b6dfd765209f4b7c8b4a7156c9e06f' 
  AND token = 'WorkSdx34xn171bVsxpQDIcwhxYwGBEsVNoFaqMEQNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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