SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92988b8fc464900607f538e07b99cf6988834e863baae1faff859320d6cb09c1' 
  AND token = 'sNFzBhiIYdAn+aDfywj/kzISQE1BzCHWlmhil+rsrOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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