SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4958e65adc0bbc53655b4024c7063afc89bd15d3dfc7098c16b7b6e4a53566ce' 
  AND token = 'DGaYs0wL2pVKDGIU8NMZk9q0NqMMoLKygxh5FZOlD4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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