SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0aeefe5d3a1d1b686428027cdb9aaeeb0896bff8cf77d0116b286fe681785a5' 
  AND token = 'HOUozV4tzdmEChvXBDoBkUEJw4SkoS6PiPjAJxlF8WY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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