SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd6cdb4756fca8eb9480bc97c2d313297f32a6c2c5d7232de423ec2a49f00c8a' 
  AND token = 'c1nkjP8drtujygV+mv5QSlLxc7/3WRtF8cSjfNnojIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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