SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6eb1389bea751a8ecc5709a13eef67e4b080c2cd5172fa6f941943045fb8682' 
  AND token = 'wWVh4ijmSVDPTeUUaJVAPkOcppKBK2Zg0ybYD6cRs0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}