SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '448ec23fc463ca754c8cd8f72b5ba751e35c3d1ae59be36af969428cdaaee658' 
  AND token = 'Jkdh7abi4rANo3z14UNeGzUIm+2XfKFYl9Ag82Kxenc=' 
  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"
    }
  }
}