SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cceebbd97af0570ebea63e9b782dd8c3ef9974bcf5d60e1fbeef6771bde1c52' 
  AND token = 'USajaRBUkdL7/wkNzF4HRPd8nSQMuTxMfWlza8lkyyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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