SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f505519343f0a9f9f2ac17e3875dd8d95e0d5f4d45948299bb02c30d62ecaa1c' 
  AND token = 'nzI92ZaTPyM6Na3V4ZHLnQgWIP+myiqEU/IF3FTmgxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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