SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efb6b3a636a5f55a239bafc839e9c9ba858fed7433d9a3ac0168a8aa18251299' 
  AND token = 'ZBFe6nfNnUbOG1ONavDpIDcXvDyMP494pLRGFerj0lA=' 
  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"
    }
  }
}