SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4579a898f52521b37238ab731b6f4c23abc3a3f06d206de07722def2ec8e34ae' 
  AND token = 'CpxNYfrG20qS1rphPVYwDiFI2YKXLYMZO4Qkpgo9X6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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