SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73e6bdd6953892c0beeb62e792605ed1c0432da67e97db5d7a633d7c0022f239' 
  AND token = 'vy/+RIJFj/lbeYOPbzJqZYW6S+GvRX/u6X2ZPrhwe8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}