SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61206c023b4f35178ef0250944112906447999d6598e1632f6d999caa469447c' 
  AND token = 'uHD0LBEfqPJzMLn2j4ls+Ozb+0QN2+LmyQfU+fgtIzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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