SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0f6f874b284ae100b6ebe471590726721838a1ba9c23b08bd80de0c7634bf5b0' 
  AND token = 'Ggbfeh3//EegcL4uhk8jMk0q++ZUkEXigKt0Wk/To+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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