SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09b4664bd4faf2b7e3770c92dffcf57a4dc96e1f9037c716ca8866ce97029418' 
  AND token = 's79Dt1Ec2GaQUWSrwUjCRbLpQb7blsc3d3JJUYYkMcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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