SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b38cd812bfa8662f40e406838525aea4c776d3866789a0648670177f12325e10' 
  AND token = 'Uhfk9D6FSKVeHluVNZudkVrX48FSUFZ/XpBAdhYqhLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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