SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09084b50ac9fc678fb160e59a6256d319e177bcf1a52cfd0615fd328f5e89f45' 
  AND token = '6ChwRJd7N/URLwtg5GkR1Cjr2tPZ20RGPKAzBfptUPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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