SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '63f474025934bbabf3edd8d40e63f15a7a6ab5d4e3612df2df1a4dcd8250c8e4' 
  AND token = 'GF+2xTMLwcAvjhLkadMSJ7bCj1y2VTTS0YJ9X+1c17w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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