SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b35200cfd04a1fc6be283e8bfc9db7a2478f4a693bb06363f9e3c9ecf53b0ce3' 
  AND token = '+IBIsTEZ01lnDDb0yBAd6s0XY236C4Www0TPQa+TuTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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