SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a56d0c7510c254f82c48e20de1e11d8aaf9a22b2c09edf3abe63e4a666ffe0f6' 
  AND token = '8y+9qiUNCENZq8Fzo4PZIVLGMBoPMwlRXHGWOph3YLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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