SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a779188b100696eaaf739bf0e33264f6ef3f1c6b67e4cd0b610a683e302ff6f' 
  AND token = 'X2GnN7OAPZPBYLHD5wUVHKK5ZXXQC/+SABqfPSNfZew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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