SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '55292d51f4013d5bf7a394a73bd2d8f0f11bacfd2962043bc812e9d1987d6ef5' 
  AND token = 'FZCpG7a+Qfh1DcMoKghxc8NoETNHMI8WLuuHOxysimw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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