SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ed46a0d64ab253cf57aadd92e4cc0315c610479ebc2783f68cf3b9de95489dc0' 
  AND token = 'QIx63HiLfXtz4yDrLWbEyAQJ3ncv+WIKHL9BnVpnrOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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