SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c918ae53bfd26ba38eabdd1b3d8c4ff9d45d558892a4bb907b8e1a0a1cd385ea' 
  AND token = 'wh7LtzlJAUb+LtKvHZUgxGjolTN73Ksx2PfUHLgySnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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