SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f822fd8cfb1070d40b1a048d692771c0fa442acd659c66f44008c3f62e46e33a' 
  AND token = 'URNMZTZp/a2D4du5FRnvMmUdlGkPm52nxk55LFzhGQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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