SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43f3b4792f56c96516bebead3b40303d577f5b0ab334cd0da1424ffe6e2aa5e3' 
  AND token = 'VNBDa5oEMIICmEtt+5TkpdLI9ME4hkn7IAgs4hcvIys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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