SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc80410aee50a798b72294d18594e2555e9665ec97a6564d61f27eba05fb18ce' 
  AND token = 'mx/n61Zth381D6GDDf7/BaE84dMi7qtUy2YU9MlJjzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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