SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e6e76333b40f86cb0f03c812bb994e078e2ebc969d0fb5e10599810d9ddbe30' 
  AND token = 'rNS2Ov1p/UVZcwhEzGLZmWlpXIDeknD4DBYQrJSV0iU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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