SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a80471df770897e19fb44ef269a1321267628d8fd2bff451ca49a5bd541fa0f' 
  AND token = 'KYJSHoQJns4jRq2kXVxXgSFcgNi+U5Adk/uUhgB8ITE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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