SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd6a14e79d789db04c48cb9129f8570eb6275988a01eee052adb5eb20045dec7' 
  AND token = 'J1R/VE4LUmgpjSm6tZJgMPxgqkKwJeuDfgfchOeop/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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