SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23a7b8d3d05277fdd365fde91d7829ec46593f507d6ebe7f2c8221530844e6e6' 
  AND token = 'WbAdjFiS9olqytKNBEUCE1Zh7UowEdVy/7s7afAsMhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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