SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20659d2f563cdec48064a570957fc5de33b3688631922be69a6919362e7db08d' 
  AND token = 'CCCb+PovYE/CUA4teQK2JcOqgfilfmbbNApYHvIWc+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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