SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59a503502f328c43a31a46591b11e58b9408c6df2a8aa864d520f43d5a8a02fe' 
  AND token = 'iFinlz2aGfqUzLGLQIAA9BIGRjldie6I8OWLsyOXYSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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