SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b68a7377e9e93fc765977dcc085a5cec309ca1bc17631ce5f60bcec319350a3' 
  AND token = '+u9vlYXIHh84AA5R6cZ+VqX/+rGYKV2FGQ8sC4L9yvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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