SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a0144961122da09a05263391b487a606b9d5852d5716e07a5ba91cce9e9f4325' 
  AND token = 'N9wJJsZYqNtXI7NtGcZuWfdQiz9VAaMlzkLnILSgn18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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