SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a1bc10f11b7bbe1a34e04193076c16974f5fb993b4532f5899eb88ed75a1694f' 
  AND token = '+FWWVGyBdke9NU1fSWv2eqo3iYQkaFZXEIut0HTFlk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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