SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59dc46e03bf61202652c7b922b278af63305aefbc56c536b3520f0db33d91e59' 
  AND token = '3QOUV29lGBD7MWS6JZWjyjOIuhJBnxCfNcoPTS2Rkvg=' 
  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"
    }
  }
}