SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6d4a9aa862f238e14f1d531a7d93e7b55741100190d6cb9306cae743f8f11490' 
  AND token = 'SZojmkd1C8/Jmov6dqthbZDK/VBEYFXawUq52OWYjfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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