SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3494c0974a31eff1a52cde998c221e6d4a6722ca61ae66d0873814ac8b3c4581' 
  AND token = 'RecJKp5zCYhZXpUeCpyNCJmG8DDCOiMVC48DnmiCYik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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