SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '745203ff635d8c59986892b3a547cfe5839c0ae1a8fe94a66d3c4282972ecd40' 
  AND token = 'cpkpZTf5YW/6JDeuEFEglJEJVcAUDMAIIQFBjnPsIJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}